Question

Kinetic energy of gas depends on:
(A) Temperature
(B) Pressure
(C) Surface area
(D) Both A and B

Answer 1

Hint: Kinetic energy of the gas is the energy associated with the movement or velocity of the molecules of the gases. The dependency of the kinetic energy on the physical parameters is given in the postulates of the kinetic theory of gases.

Complete step by step solution:
The energy associated with the velocity of the particles or movement of the gas molecules is called kinetic energy of the gases. It has been found that the particles of the gas are in constant rapid motion.
- The kinetic energy is variable with one physical parameter and it is temperature.
- As we increase the temperature of the system, the velocity of the particles increases and as a result, their kinetic energy increases. Same way, as we decrease the temperature of the system, the kinetic energy of the gas decreases.
- Thus, the average kinetic energy of the gases depends only upon the absolute temperature of the system. The temperature and the kinetic energy of the system are related with the following equation.
\[K.E. = \dfrac{3}{2}nRT\]
 Where K.E is the kinetic energy of the gas
n= number of moles of the gases
R= Universal gas constant
T= temperature in Kelvin
- Change in surface area has no effect on the kinetic energy of the gas.
Thus, we can conclude that kinetic energy of the gas depends only upon the temperature.

So, the correct answer to this question is (A).

Note: Do not assume that as pressure and temperature of the system are related with each other, both will have an effect on the kinetic energy. In reality, changes in pressure do not affect the kinetic energy of the gases.